The first of Snow and McAdam's four possible identity construction processes is 'identity amplification', which:

involves the embellishment and strengthening of an existing identity that is congruent with a movement's collective identity but not sufficiently salient to ensure participation and activism.

For a Jewish believer to feel comfortable in church, he/she must have the church-liking part of them strengthened. Perhaps they have had previous experience of church - as a child or before they knew they were Jewish - and this can be reached and amplified. Snow and McAdam explain:

The identity that has now moved centre stsge was not foreign to the oerson's biography. Rather, it may have been a significant, moderately salient, or peripheral identity in one's past.

The more this identity can be amplified, they say:

the stronger the identification with the movement and the more blured the distinction between personal identity and collective identity.